ORL000001 CDMA Basic Communication Flow(NSS)ISSUE1.0

HUAWEI TECHNOLOGIES CO., LTD.

All rights reserved

www.huawei.com

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ORA000001 CDMA Basic Communication Flow

(NSS)

ISSUE 1.0

HUAWEI TECHNOLOGIES CO., LTD. Page 2All rights reserved

Upon completion this course, you will be able to:

Understand the basic flows of CDMA.

Understand the meaning of important

parameters.

Improve the problem analysis and fault locating

capabilities according to the flows.

Memorize the abbreviation of signaling

messages..


References

CSOFTX3000 Technical Manual-

Service Procedures


Chapter 1 Brief Introduction of CDMA FlowsChapter 1 Brief Introduction of CDMA Flows

Chapter 2 Procedures for Mobility ManagementChapter 2 Procedures for Mobility Management

Chapter 3 Procedures for Security Management Chapter 3 Procedures for Security Management

Chapter 4 Procedures for Basic Call Service and Chapter 4 Procedures for Basic Call Service and

Short Message ServiceShort Message Service

Chapter 5 Procedures for Intelligent Network SerChapter 5 Procedures for Intelligent Network Ser

vicesvices


Brief introduction of CDMA flows

Basic CDMA flows

Registration flows

Authentication flows

Calling flows

Handoff flows

Supplementary service flows

Short message flows


Brief introduction of CDMA flows

The flows that the main services may involved in are as follows:

Mobile phone power on/off: location updating flows and authentication flows

Mobile phone calling: calling flows and authentication flows (IN flows)

Migration in the conversation: handoff flows and authentication flows

Short message: short message flows and authentication flows

Supplementary service: supplementary service flows and authentication

flows








vicesvices


Overview of Mobility Management

The network supports and manages mobility of a MS to:

Determine the current location of the MS.

Optimize the connection between the MS and network.

Roaming means that a MS changes the connection to a cell

and to the network. According to different statuses of a MS,

mobility management falls into location management and

handoff management.


Location Management

It is necessary to confirm the current location of an idle MS. Location management helps the MS to be connected to the calling party promptly and helps the network keep tracing and store the current location information of a MS. Location management guarantees the consistency of the location information stored in the HLR, MSC/VLR, and MS.

The HLR stores information on subscriber registration and location.

The VLR stores the information loaded from the HLR, including the subscriber registration, location, and status.

The MSC processes the flow of location registration and exchanges data with the VLR.

The MS stores information on its location area.


Location Registration

Location registration takes place in the following cases:

A MS is switched on.

BSS

Location_ updating_ request

Location_ updating _ accept

MSC / VLR HLR

REGNOT

regnot

IMSI, ESN,calling & called address (SPC)

Registration type, AUTHR, IMSI, ESN, MSCid

auth para required

IMS, MDN,calling feature Indicator, trigger


Deregistration Deregistration can be initiated by the MS or by the VLR:

Upon receipt of a MS power-off or inactivity indication, the MSC determines the MS needs deregistration.

The MSC/VLR removes all records of the MS from the VLR and sends an MSINACT message to the HLR.

The HLR returns an msinact message to confirm the deregistration.

MSC/VLR

MSINACT

msinact

HLR


Location Registration (NORMAL)


A MS moves beyond the paging coverage area of the previous location area.

LA1 LA2

MS

MSC

Locati on_Updati ng_Request




A MS moves beyond the paging coverage area of the

previous location area.

BSS

Location_updating _ request

Location_ updating_ accept

MSC/VLR N HLR MSC/ VLR O

REGCANCREGNOT

regcanc

regnot




Besides, a MS timely initiates a periodic location registration.

BSS

Location _ updating _ request

Location _ updating _accept

MSC / VLR


Questions

Whether VLR need to send all the location registrations to

HLR ? And why?

What is the meaning of MSCID in the location registration

message, and what is the function ?

Why does the switch off message need to be registered ?


Answers Question 1: Not all the requests of location registrations are sent to HLR. If the

subscriber’s data has already existed in VLR and the subscriber is activated, the registration is processed by VLR. Otherwise the registration requests are sent to HLR, and processed by HLR.

Question 2: MSCID is the identification of MSC mainly including SID (System Identification) and SWNO (Switch No.). It uniquely identifies one switch entity, and is used to determine whether the MS is roaming.

Question 3: Switch off registration are mainly used to inform HLR that the subscriber has already powered off. If other subscribers call it, system can send the access refuse directly to the calling party according to the subscriber’s status in HLR.


HandOff flow on A interface in one BSC


HandOff flow on A interface between BSCs


Forward HandOff


Backward HandOff


HandOff to Third Party


Questions

What is the difference between Forward HandOff and Bac

kward HandOff?

When does the third parties handoff happen?

What is the main function of FACDIR ？


Answers Question 1: the Forward Handoff is that MS handoff from the serving MSC

to a new target MSC; and the Backward HandOff is that MS handoff from the serving MSC to the primary controlling MSC.

Question 2: Whether HandOff to Third Party happens depends on the startup standard value of Third Party HandOff and handoff depth together, when the current handoff times, viz. the handoff depth equal to the startup standard value of Third Party Handoff, the MS will handoff to the third party.

Question 3: FACDIR is used to set up inter_office handoff circuits, which is MAP circuit.




Chapter 3 Procedures for Security ManagementChapter 3 Procedures for Security Management




vicesvices


Basic Security Management Procedure

This chapter describes functions, principles, and message flows of security

management in the CSOFTX3000. :

Security management of the CSOFTX3000 includes the following:

Authentication

Authentication protects the system resources from illegal users.

Through authentication, the system verifies subscriber validity.

Authentication parameters:

A_Key SSD

RAND/RANDU/RANDBS/RANDSSD

RANDC AUTHR/AUTHU/AUTHBS

COUNT AUTHDATA


Authentication Principle

For the same algorithm and input on both mobile station (MS)

side and network side, the output results must match. The

principle of CDMA authentication is to compare the output

results by using a same algorithm on the two sides. If the

outputs match, the authentication succeeds.


Mobile Station Access Authentication Procedures

BSS MSC/VLR HLR/AC

Location Updating Request

AUTHREQ

authreq

REGNOT

regnot

Location Updating Accept

Procedure for authentication upon location registration.



Procedure for authentication upon call origination.

BSS MSC/VLR HLR/AC

CM Service Request

AUTHREQ

authreq

Assignment Request

Assignment Complete



Procedure for authentication upon call termination.

BSS MSC/VLR HLR/AC

Paging Request

Paging Response

AUTHREQ

authreqAssignment Request

Assignment Complete








vicesvices


Basic Call Procedures

This section describes the procedures for the

following four types of calls:

Intra-Office Calls

Inter-Office Calls

Calls from PLMN to PSTN

Calls from PSTN to PLMN


Intra-Office Call Procedures (TDM-BASED)

BSC - O MSCe MGW HLR BSC - T

1 . CM Service Request

4 . LOCREQ5 . locreq6 . Paging Request

2 . Add Request

7 . Paging esponse

3 . Add Reply

8. Assignment Request

9. Assignment Complete

16 . CONNECT

13 . Assignment Complete14. Modify Request15. Modify Reply

12 . Assignment Request

10 . Add Request11 . Add Reply

17 . Modify Request18 . Modify Reply

Conversation


Intra-Office Call Procedures (TDM-BASED)

Conversation

19 . Clear Request

20 Subtract Request

21 Subtract Reply22. Clear Command

25. Subtract Request

27. Subtract Reply

23 . Clear Complete

24 . Clear Command

26 . Clear Complete

.

.

BSC - O MSCe MGW HLR BSC - T


Inter-Office Call Procedures BSC MSCe- O MGW- O HLR MSCe- T MGW- T BSC

CM Service Request

LOCREQ ROUTREQ

routreqlocreq

Add RequestAdd Reply

Assignment RequestAdd Request

Add ReplyAssignment Complete

INVITE100

Paging RequestPaging Response

183PRACK for 183

200 for PRACK

180PRACK for 180

200 for PRACK

CONNECT200 for INVITE

Modify RequestModify Reply

ACK for 200Conversation

Clear Request BYESubtract RequestSubtract Reply

200 for BYEClear CommandClear Complete

Notify ReplyNotify RequestNotify Reply



Assignment RequestAssignment Complete

Notify Request



Subtract RequestSubtract Reply


Clear CommandClear Complete



Calls from PLMN to PSTN

BSC MSCe MGW PSTN

CM Service RequestAdd Request

Add ReplyAssignment Request


Assignment CompleteIAM

ACM

RELConversation

RLCSubtract Request

Subtract ReplyClear Command

Clear Complete

ANM

Subtract Request

Subtract Reply


Calls from PSTN to PLMN PSTN GMSC HLR MSCe MGW BSC

IAM LOCREQROUTREQ

routreqlocreqIAM

Paging RequestPaging Response


Clear CommandClear Complete

ACMACM Modify Request

Modify ReplyCONNECT

ANMANM

ConversationClear Request

Subtract RequestSubtract ReplyREL

REL

RLCRLC

Assignment RequestAssignment Complete





Questions

What is the difference between the local call and inter-office call?

Please describe the flows triggered when the MS registered in

Beijing makes a call in Shenzhen.


Answers

Question 1: There are two essential differences between Intra-office mobile

calling and Inter-office mobile calling: one is that whether the location reques

t message carry the TLDN or not, local office assigns the TLDN in intra-office

calling flows, the called office assigns the TLDN in inter-office calling flows; t

he other is that whether the signals route outgoing according as the TLDN.

Question 2: Location Register flow, Authentication flow, Calling flow


Basic Short Message Procedures

The SMS procedures involve processing the following:

Mobile originated short message

Mobile terminated short message

Short message notification

Short message broadcast


Mobile Originated Short Messages

MS MSC / VLR MC HLR MSC / VLR MS

SMDPP

smdpp

SMSREQSMSREQ

smsreqsmsreq

SMDPP

SMD - REQ

SMD - ACK

smdpp

SMD- REQ

SMD- ACK


Mobile Terminated Short Messages

MS BSC MSC/ VLR HLR MC SME

system access Location UpdatingRequest

REGNOT

regnotLocation UpdatingAccept

SMDPP

smdppSMSREQ

SMSREQ

smsreqsmsreq

SMDPPSMD- REQ

SMD- ACK

smdpp








vicesvices


PPC Service Procedures in Target Network

The PPC service enables a subscriber to open an account and activate voice services by paying beforehand or buying a rechargeable card of a certain value.

Before a call is connected, the system accepts or rejects the call request according to the subscriber's account balance.

During the call, the system decreases the subscriber's account balance for the charge real-time for voice services or other services .

When the account balance reaches a threshold, the system disconnects the call and plays an announcement.


Calls Originated from PPC Subscribers MGWMSCe SCP

CM Service RequestORREQ

orreqANLYZD

SEIZERESseizeres

CONNRES

Add Request

Add ReplyAssignment RequestAssignment Complete

INSTREQ

SRFDIRModify RequestModify Reply

srfdirinstreqanlyzd

OANSWER

conversation

ODISCONNECT

odisconnect

MS disconnect



Calls Terminated by PPC Subscribers MSCe HLR SCP

Call originationLOCREQ

locreq

ANLYZD

anlyzd

LOCREQ

locreq

ANLYZD

anlyzd

TANSWER

conversation

TDISCONNECT

tdisconnect

MS answer

MSdisconnect


Understand the basic flows of CDMA

Understand the meaning of important

parameters

Memorize the abbreviation of messages

SummarySummary

www.huawei.com

Thank You

Documents

ORL000001 CDMA Basic Communication Flow(NSS)ISSUE1.0